Scenario analysis of the Use of Biomass-based Bags for Household Waste Collection

( J. Yano ),( S. Sakai ) 한국폐기물자원순환학회(구 한국폐기물학회) 2017 한국폐기물자원순환학회 심포지움 Vol.2017 No.1

Interest in biomass-based materials is increasing, since they can contribute to reducing greenhouse gas (GHG) emissions and fossil fuel consumption. Although polylactide (PLA) was historically one of the most well-known and major materials, biomass-based polyethylene (Bio-PE) use has rapidly expanded. In Japan, introducing Bio-PE is expected to be an effective measure to achieve the target to reduce GHG emissions by 26% by 2030 compared to 2013. Waste collection bags are one candidate that can be replaced with biomass-based materials. In this study, we aimed to estimate the reduction potential of GHG emissions using a life cycle analysis. Kyoto, Japan, was selected as a case study. The functional unit was the supply of plastic bags to collect 223,717 tons of household waste generated in the city of Kyoto in 2014. Bio-PE made from sugarcane ethanol and PLA made from com were considered as the biomass-based materials. We assumed that PLA was blended with polybutylene succinate-co-butylene adipate (PBSA) derived from fossil fuels to a final proportion of 70% to reinforce the flexibility. The system boundary extended from cultivation, production of plastic pellets, to final disposal, and excluded consumer use of the plastic items. We assumed that Bio-PE and PLA were produced in Brazil and the United States, respectively, and imported. We considered six scenarios based on three waste collection systems: one scenario for mixed waste collection, i.e.,no source-separated collection (S1F, baseline scenario); two scenarios in which plastic containers and packaging (C&P) were source-separated (S2F and S2B); and three scenarios in which food waste was additionally source-separated (S3F,S3B, and S3B+P). In S3B+P, PLA was used to collect source-separated food waste while bio-PE was used to collect source-separated plastic C&P and the remaining waste. The amount of bags consumed in each scenario to meet the functional unit was calculated using household waste composition and the density of the waste fraction as the filling rate per bag. In the results, if Bio-PE were introduced like as S2B,GHG emissions could be reduced by 92.5% compared to S1F. Similarly, S3B could reduce GHG emissions by 92.2%. This implied that the effect of introducing source-separated collection of food waste was relatively small, as the amount of bags consumed did not differ substantially. GHG emissions in S3B+P, which used both Bio-PE and PLA as biomass-based materials, were estimated to be reduced by 90.7% compared with S1F. Although the Bio-PE bags in S3B had to be removed during AD pretreatment, and resulted in lower quality AD residue, the PLA bags in S3B+P could be recycled with AD with food waste. Therefore S3B+P would offer additional benefits besides GHG reductions.

Life Cycle Assessment for Small-scale Anaerobic Digestion System - Case study in Small municipality -

( J. Yano ),( S. Sakai ) 한국폐기물자원순환학회(구 한국폐기물학회) 2019 한국폐기물자원순환학회 심포지움 Vol.2019 No.1

Food waste is significant in Japan. For example, 17.4 million tons, including 11 million tons from households, was generated in 2010 alone (MAFF, MOE 2013). Of this, 10 million tons of food waste from households is currently incinerated. To develop cleaner production cycles, waste-to-energy should be considered. On-site small-scale anaerobic digestion (AD) facility can be applied for small municipalities where they have demand of not only electricity but also heating. This study evaluates the environmental impacts of on-site AD of food waste in small-scale municipality using a life cycle assessment (LCA). Small municipality with 27,000 of population was selected as case study. The functional unit is the “treatment of 4 ton/day household food waste generated in the municipality.” The system boundary is considered to include the collection to the treatment of food waste. Totally 8 scenarios consist of 6 sub-scenarios considering treatment methods of AD residue and wastewater were developed. For AD residue treatment, treatment in the excreta treatment facility within the municipality, composting outside the municipality, and incineration outside the municipality, were considered. Incineration and composting were also included as reference treatment methods. For small AD, biogas is used as a source of electricity and heat through a combined heat and power (CHP) system. Global warming, fossil fuel consumption, urban air pollution, and acidification were considered as environmental impacts. After the characterization of each impact category, a damage assessment for the four different dimensions including human health, social assets, biodiversity, and primary production, was considered. Then, the results of these individual dimensions were integrated by conversion into a single index with units of value in Japanese yen (JPY). The calculation utilized characterization, damage, and integration factors are identified by the LIME2 model (JLCA 2012). Concerning global warming, CO₂ emissions derived from biomass are considered to be carbon-neutral and thus have been excluded from the calculation. The results of the integration in Fig. 1 revealed that the small-scale AD system (Scenarios 3 and 4) showed environmental benefit (negative values). Regarding the comparison with the treatment methods of AD residue and wastewater, S4-3 (composting of AD residue) was the most desirable while S4-4 (incineration of AD residue) was the worst. Among the environmental impacts, global warming tended to be the dominant in scenarios 4-1 to 4-4.

Steady wind force coefficients of inclined stay cables with water rivulet and their application to aerodynamics

S. Sakai,M. Matsumoto,T. Yagi,Jun Ohya,Takao Okada 한국풍공학회 2005 Wind and Structures, An International Journal (WAS Vol.8 No.2

The Blue and Red Luminescences from Ambient Air Aged Porous Silicon

Chang, S.S,Yoon, S.O,Choi, G.J,Kawakami, Y,Sakai, A The Korean Ceramic Society 1998 The Korean journal of ceramics Vol.4 No.1

This paper reports on photoluminescence (PL), luminescence decay curves, and compositional analysis of porous silicon(PS) which is aged under air ambient by Fourier transform infrared vibrational spectroscopy (FTIR) and by Auger electron spectroscopy (AES). Porous silicos which has been aged under air ambient yields two PL band structures, i.e. blue/violet PL and red PL. The evolution of a blue/violet band is pronounced, especially for thin PS film which is prepared in dilute HF solution. The blue/violet PL band has been observed initially to increrase rapidly with aging, then saturated with further atmospheric aging. The ambient air aged PS exhibits a fast decay time of sub-nanosecond at room temperature and shows appreciably faster decay time than that at 20K. Atmospheric aging of this thin blue/violet luminescing PS yield non-stoichiometric oxide judging from the vibrational spectra of Si-O and AES analysis.

Growth differentiation factor 11 signaling controls retinoic acid activity for axial vertebral development

Lee, Y.J.,McPherron, A.,Choe, S.,Sakai, Y.,Chandraratna, R.A.,Lee, S.J.,Oh, S.P. Academic Press 2010 Developmental Biology Vol.347 No.1

Mice deficient in growth differentiation factor 11 (GDF11) signaling display anterior transformation of axial vertebrae and truncation of caudal vertebrae. However, the in vivo molecular mechanisms by which GDF11 signaling regulates the development of the vertebral column have yet to be determined. We found that Gdf11 and Acvr2b mutants are sensitive to exogenous RA treatment on vertebral specification and caudal vertebral development. We show that diminished expression of Cyp26a1, a retinoic acid inactivating enzyme, and concomitant elevation of retinoic acid activity in the caudal region of Gdf11<SUP>-/-</SUP> embryos may account for this phenomenon. Reduced expression or function of Cyp26a1 enhanced anterior transformation of axial vertebrae in wild-type and Acvr2b mutants. Furthermore, a pan retinoic acid receptor antagonist (AGN193109) could lessen the anterior transformation phenotype and rescue the tail truncation phenotype of Gdf11<SUP>-/-</SUP> mice. Taken together, these results suggest that GDF11 signaling regulates development of caudal vertebrae and is involved in specification of axial vertebrae in part by maintaining Cyp26a1 expression, which represses retinoic acid activity in the caudal region of embryos during the somitogenesis stage.

Effects on Bone Regeneration When Collagen Model Polypeptides Are Combined with Various Sized Alphatricalcium Phosphate Particles

Sakai K,Hashimoto Y,Baba S,Nishiura A,Matsumoto N 대한치과재료학회 2011 대한치과기재학회 학술대회 Vol.2011 No.5

Crop - row Detection by Color Line Sensor

S . Hata,M . Takai,T . Kobayashi,K . Sakai 한국농업기계학회 1993 ICAMPE 요약집 Vol.2 No.-

와권(渦卷)노즐의 이론분석(理論分析)(2) -분무각(噴霧角) 및 유량계수(流量係數)에 관하여-

이상우 ( S W Lee ),판정순 ( Jun Sakai ) 한국농업기계학회 1988 바이오시스템공학 Vol.13 No.3

咳霧量 및 流量孫數에 關한 많은 硏究가 實驗結果資料에 기초하여 遂行되어졌다. 그러나 供試體의 노즐의 特性에 따라서 流線의 特性이 다르므로 많은 實驗結果 및 解析이 서로 상치되는 점이 많다. 本硏究에서는 理論分析結果가 實驗結果와 다소 다르더라도 노즐 設計의 實際應用面에서 必要한 노즐構造의 基本機能을 理論的으로 分析,理解시키고저 한다.

Lp-CONVERGENCE OF HIGHER ORDER HERMITE OR HERMITE-FEJÉR INTERPOLATION POLYNOMIALS WITH EXPONENTIAL-TYPE WEIGHTS

H. S. Jung,R. Sakai 장전수학회 2015 Advanced Studies in Contemporary Mathematics Vol.25 No.3

Let R = (-, ∞), and let Q ∈ C1(R) : R → R+ = [0, ∞) be an even function, which is an exponent. We consider the weight wρ(x) = |x|ρe-Q(x), ρ > 0, x ∈ R, and then we can construct the orthonormal polynomials pn(w2ρ; x) of degree n for w2ρ(x). In this paper we obtain Lp-convergence theorems of even order Hermite-Fejér interpolation polynomials at the zeros {xk,n,ρ}n k=1 of pn(w2 ρ; x). Let R = (-, ∞), and let Q ∈ C1(R) : R → R+ = [0, ∞) be an even function, which is an exponent. We consider the weight wρ(x) = |x|ρe-Q(x), ρ > 0, x ∈ R, and then we can construct the orthonormal polynomials pn(w2ρ; x) of degree n for w2ρ(x). In this paper we obtain Lp-convergence theorems of even order Hermite-Fejer interpolation polynomials at the zeros {xk,n,ρ}n k=1 of pn(w2 ρ; x).

IMAGING A SCENE FROM EXPERIENCE GIVEN VERBAL EXPRESSIONS

Y.Sakai,M.Kitazawa,S.Takahashi 제어로봇시스템학회 1995 제어로봇시스템학회 국내학술대회 논문집 Vol.1995 No.10